Art of cracking hydrocarbons



J. W. COAST, lk. ARI oF CRACKING mfnfiocARBoNs.v

APPLIICATION FILED SEPLZT, |1917.

1,370,881. Patented Mar.8,'19211 Figi- HEATING CHAMBER H EATING CHAMBERv l E jimmy/fs- TES JOH'N W. COAST, JR.,OF TULSA, OKLAHOMA, ASSIGNOR TO THE PROCESS PATENTol-F lcs- TULSA, OKLAHOMA, ACORPORATION OF MARYLANI).

AART OF CRACKIENG HYDROCARBON'S.

To' all w hom t may concern.' V l l Y Be it known that I, JOHNA W. COAST, r., a citizen of the United AStates of America, a

resident of Tulsa, in the county of Tulsa,

State of Oklahoma, have invented certain new and useful'lmprovements in the Art of Cracking Hydrocarbons, of which the following is a full, clear, and exact description, reference being had to. the accompanying drawing, forming a part of this specifica-` tion.

This invention relatesto improvements in the art of cracking hydrocarbons, the main object being to protect cracking stills from the injurious effects of carbon or tarry substances known inthe art as coke and cokeforming matter.

Another object is to circulate the oil undergoing distillation, thereby economizing in the use of fuel, maintaining th'e oil at a .substantially uniform temperature throughout the still, and enabling the temperature to be raised quickly at the beginning of the distilling operation.

A further object is to enable the apparatus pressure and 'at a high temperature, the

heavy coke-forming fractions drop by gravity to thebot-tom of the still, and in following the ordinary practice, .the coke orv carbon is permitted.' to accumulate on the still bottom, directly above the fire. vOne of the important problems in this art lies in the elimination of largebodies of coke or car- ,.bon, from the hottest partsof cracking stills.

The coke or carbonis an insulating substance,

preventing the free transmission' of heat from the still bottom to the oil, thus decreasing the eiiiciency of the heating mediuml and when a suliicient quantity of the insulating substance accumulates in the still,

the still bottom becomes red hot. 'Someimmediate steps must then be taken to avoid a rupture at the overheated portion of the Specification of 'Letters Patent.

' `Patented Mar.'8, 1921.

Application med septemberav, 191'?.v serial No. 193,454. l

still. Owing to the high pressure and temperature of the oil in the still, the accumu- COMPANY, or f lations of coke vor carbon have, heretofore,

rendered cracking operations quitev dangerous. l

The present invention-entirely eliminates this danger,A and at the same time obtains a number of other very important advantages,

all of which are highly desirable in the manufacture of gasolene from relatively heavy petroleum distillates and residues.

Figure I is a diagrammatica'l view of a cracking apparatus adapted for use in carrying out the new method.

Fig. II isan enlarged longitudinal section` of the still.

Fig. VIII is an enlarged section of the screen orfilter. 'l

In the apparatus shown to" illustrate the invention, a large cylindrical still `l is arranged above a heating chamber 2, and connected by means of a vapor pipe 3, to an air cooledreflux condenser 4. l5 vdesignates a vapor` pipe leading from the reflux condenser 4 to a main condensing coil 6, from which the low boiling point product is recovered. The condensing coil 6 is preferably arranged in awater tank 7.

The apparatus herein shown is particularly adaptedfor use in cracking high boiling point products of distillation'such, for

example, as distillates lory residues resulting from the distillation of crude petroleum. The substance to be treated is introduced into the still in any suitable manner, and any'desired pressure may be obtained by regulating a valve 8, preferably located in the vapor pipe'. The pressure in the still, is preferably greaterthan 50 'pounds per Vsquare inch, for example, about 80 pounds per 'square inch, and the temperature of the contents of the still preferably 4ranges from about 600o F. to 800o F. Heat generated in the heating chamber 2 is-transmitted directly through-the still bottom to the liquid contents -of the still. The low boiling'point vapors passing from the liquid, flow throughy the vapor pipe 3 and reflux condenser 4 to the pipe 5,v leadingto themain condenser 6 from which the low boiling point product is recovered. The relatively high boiling pointfractions; are condensed in the vapor pipe 3 or in the condenser 4, such fractions being returned, by gravit-y, through the .vapor pipe 3. The heating chamber 2 may be Droits ength.

vided with a. gm@ e Ola which a bed of fuer `is maintained.

f connected to the intake p ipe 9, and provided with a discharge pipe 12 leading to a screen or filter-AA, the latter being provided with a discharge pipe 13.' The pump and filter, as well as the pipes 9, 12 and 13, are preferably located-in the still and submerged in the liquid contents thereof. power shaft 14, passing through a stuffing boi\v 15 at one end of the still, may be rotated to'aotuate the pump 11. A pinion 1G fixed' to the inner end of shaft 14, meshes with an operating wheel 17on the pump, and this shaft 14 may be rotated by transmitting power to a wheel -18 at the exterior of the still.

The filter, or strainer, A comprises ascreen 19 arranged in a housing 2O wherein the coke-forming matter is separatedl from the oil'. The filter or strainer may also include a layer ofpmineral wool 21 arranged above the screen 19, and a layer of fullers earth 22 between the mineral wool andthe top wall of the housing 20. To obtain the'A highest efficiency, a large filter'should 'be' used and. its capacity should enable the distillation to be carried on for a considerable period of time without removing the cokeforming matter from the filter. I

lVhile the oil is-undergoing distillation, the rotary pump 11-is operated continually, thereby drawing oil and coke-forming matter-through the ports 10 in the' intake pipe near the hot still bottom,'the stream of oil and coke-forming matter being -drawn to the pump. 11, and discharged through the pipe 12, t the filter A. The free carbon, or coke-forming matter, accun'iulates in the filter A, and the filtered oil is constantly discharged from the pipe 13 to the main body of-oil in the still. A relativelyl small stream of oil is thus maintained in circulanow be understood that this invention entirely eliminates the danger usually due to an accumulation of coke or carbon in the still, thereby greatly increasing the life of the still, i'ncreasing'the efficiency by taking away the heat insulating matteil from the place at which the heat 1s transmitted through the still, and enabling the still to be recharged and run continuously for a considerable period of time without cooling the apparatus, and without removing the residue. 4

By forcibly circulating a relatively 'small stream of oil in the main body of the oil, herein disclosed, a general circulation of all of the oil is maintained The hot oil entering the pipe 9 is drawn toward one end of the still. then upwardly to the pump and thereafter' discharged toward the .oppol' Owing to the manner site end of the still. in which the oil is circulated, a substantially uniform temperature is maintained at all lining a body of hydrocarbon oil in a cracking still, heating the bottomof the still to vaporize the oil, condensing the vapor, maintaining the conten-ts of the still under pressure, forcing a stream of oil and cokeforming matter from the heated lower portion of the still, filtering said stream to sep arate the coke-forming matter from the oil, at the same time maintaining the stream of oil and the coke-forming matter at the temy perature of the contents of the still and discharging the filtered oil into the main body of oil in thev still, the circulating stream being completely inclosed within the still to avoid cooling of the. oil.

In testimony that I claim the foregoing I hereunto affix my signature.

JOHN'V. COAST, JR. 

